Cicendia is a small genus of flowering plants in the gentian family (Gentianaceae), order Gentianales. Described by Michel Adanson in 1763, it contains two to three accepted species of tiny yellow annual wildflowers. The plants are diminutive — the most widespread species, Cicendia filiformis (slender cicendia or yellow centaury), reaches only 2–12 cm in height and bears narrow linear leaves 2–6 mm long. Its four-petaled yellow flowers, sometimes tinged with pink, open only in direct sunlight. The second commonly recognized species is Cicendia quadrangularis (Oregon timwort), native to western North America and South America; a third, Cicendia stricta, is recognized by some authorities. All are annuals of open, periodically wet habitats.
Etymology
The name Cicendia comes from the old Tuscan (Italian) plant name kikenda, recorded by Dioscorides, referring to an unknown gentian-like plant. The genus was formally published by French naturalist Michel Adanson in 1763 in his Familles des Plantes.
Distribution
Cicendia has a disjunct, multi-continental distribution. Cicendia filiformis is native to Western and Mediterranean Europe and has naturalized in southern Australia; within the UK it is restricted to heathlands in southwestern England, southern England, and parts of Wales, where it has become extremely rare or rapidly declining in several counties. Cicendia quadrangularis is native to western North America and South America. The genus thus spans Europe, North America, South America, and Australia.
Ecology
Cicendia species are annuals of open, seasonally wet, low-competition habitats. C. filiformis is found around seasonally-flooded pools, along rutted tracks, and on lowland heathlands with acidic, sandy, or peaty soils. It thrives where free-roaming grazing animals keep competing vegetation in check and is often associated with other declining specialist species such as three-lobed water-crowfoot (Ranunculus tripartitus), chaffweed (Anagallis minima), allseed (Radiola linoides), and pillwort (Pilularia globulifera), indicating a shared reliance on a now-scarce habitat type.
Taxonomy Notes
The genus Cicendia was described by Michel Adanson and published in Familles des Plantes, volume 2, page 503, in 1763. While the core list includes C. filiformis (L.) Delarbre and C. quadrangularis (Lam.) Griseb., Spanish Wikipedia also accepts C. stricta Griseb. as a third species, suggesting some taxonomic uncertainty in the circumscription of the genus. The type species is Cicendia filiformis, originally described by Linnaeus as Gentiana filiformis before Delarbre transferred it to Cicendia.
